Experiment to investigate how the number of turns on a coil affects the strength of an electromagnet
I think that increasing the number of turns on a coil will increase the strength of the electromagnet. I believe that strength will be directly proportional to the number of turns.
We wrapped a wire around an iron nail and connected it to a D.C power supply. Keeping the voltage constant, we recorded how many paper clips the electromagnet could pick up in a chain.
Increasing the number of turns in the coil of wire did increase the strength of the electromagnet. For example at 20 turns, it could pick up 1 paper clip but at 80 turns it could pick up 3 paper clips. It needed on average another 25 turns to pick up another paper clip.
This was not a very reliable experiment: we could have improved the reliability of our data by taking repeats.
Our results are not very accurate as the method of measurement was not very precise. The largest source of error was our paper clips. We could only measure strength to the nearest paper clip. We could have improved this by using smaller paper clips. Care was taken to make the test more accurate by picking up a chain of paper clips rather than a clump.